Tread Wear Indicators For Outsoles Of Footwear

ABSTRACT

A polymeric outsole for an article of footwear comprises: an outsole body and a tread pattern that comprises a plurality of cleats and channels between the cleats; and one or more tread ribs projecting from the outsole body. The tread ribs project a first distance from the outsole body that is shorter than a second distance that the cleats of the tread pattern project from the outsole body. The tread ribs are effective as wear indicators to indicate remaining useful life of the cleats. During a first duration of wear, the tread ribs are not in contact with a ground surface while the cleats are in contact with the ground surface, and during a second duration of wear, both the tread ribs and the cleats are in contact with the ground surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 62/450,834, filed Jan. 26, 2017, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure generally relates to outsoles having tread wear indicators. A tread rib is adjacent to a projection feature of an outsole's tread pattern. The tread rib protrudes a first distance from an outsole body that is shorter than a second distance that the adjacent projection feature protrudes from the outsole body. Wear of one or more projection features, which may be a cleat, a heal, a heal strike, and the like, is indicated by the relative height of the tread rib to the adjacent projection feature.

BACKGROUND

Personal protective equipment (PPE) includes articles of footwear, which have many varying features depending on expected conditions that will be encountered by the footwear. Risk of slipping and falling is one hazard that PPE footwear is usually designed to safeguard against. Tread patterns of footwear can offer slip resistance over a wide range of surfaces such as dry, wet, and/or contaminated surfaces. Outsoles made from polymeric material and used in PPE footwear can erode during the course of wearing the PPE footwear.

There is a need to provide tread wear indicators for safety and inventory purposes.

SUMMARY

Provided are outsoles with one or more tread ribs that are effective as tread wear indicators.

In an aspect, a polymeric outsole for an article of footwear comprises: an outsole body and a tread pattern that comprises a plurality of projecting features and channels between the projecting features. There is a first tread rib adjacent to a first projecting feature, the first tread rib protruding a first distance from the outsole body that is shorter than a second distance that the first projecting feature protrudes from the outsole body.

A detailed aspect provides: a polymeric outsole for an article of footwear comprises: an outsole body and a tread pattern that comprises a plurality of projecting features and channels between the projecting features. A first tread rib is adjacent to a first projecting feature selected from the group consisting of: a toe, a heel strike, and a cleat; the first tread rib being in a first channel of the outsole body and protruding a first distance from the outsole body that is shorter than a second distance that the first projecting feature protrudes from the outsole body. The first tread rib is effective as a wear indicator to indicate remaining useful life of the first projecting feature whereby during a first duration of wear, the first tread rib is not in contact with a ground surface while the first projecting feature is in contact with the ground surface, and during a second duration of wear, both the first tread rib and the first projecting feature are in contact with the ground surface.

In another aspect, an article of footwear comprises any polymeric outsole disclosed herein and an upper affixed to the outsole.

A further aspect is a method of making an article of footwear comprises: obtaining any polymeric outsole disclosed herein and affixing an upper to the outsole.

Another aspect provides a method of providing tread wear indication, the method comprising: obtaining any article of footwear disclosed herein; wearing the article of footwear; and observing the tread rib relative to the projecting features for an indication of remaining useful life transport of the projecting features.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic front view of an outsole according to an embodiment;

FIG. 2 is a schematic front view of an outsole according to another embodiment;

FIG. 3 is a schematic close-up view of the outsole of FIG. 2;

FIG. 4 is a schematic cross-section view of the outsole of FIG. 2; and

FIG. 5 is a plan side view of a boot comprising an outsole.

DETAILED DESCRIPTION

Polymeric outsoles disclosed herein have an advantage in that a tread rib is effective as a tread wear indicator, providing a visual indication of remaining useful life of projection features of a tread pattern. The tread wear indicator may be used by the wearer to visually indicate when the tread pattern (e.g., cleats and other projecting features) has sustained abrasive wear. For example, when a tread rib is designed to be 50% of the height of an adjacent cleat and when the tread rib becomes level with the adjacent cleat after period of use, it is understood that the cleat has been worn to 50% of its original thickness. From there, it can be gauged as to when the boots will need replacing. As disclosed herein, the tread rib will be a shorter height than the surrounding or adjacent projection features, the degree to which it is shorter will depend on the application.

Outsoles having tread ribs are suitable for all types of articles of footwear for which an indication of wear would be useful. These articles have uppers that can be assembled with polymeric outsoles.

A “cleat” is a feature of an outsole, which is integral to a body of the outsole protruding from a surface of the outsole for traction purposes. An array of cleats and channels therebetween at least constitute a tread pattern. The cleats and overall tread pattern affords the wearer slip resistance over a wide range of surfaces.

A “tread rib” is a feature of an outsole that provides an indication of tread wear in that when the tread rib is even with one or more cleats of the outsole, an indication of remaining useful life is provided. The tread rib does not provide significant traction or fluid directing and is intended to minimize impact on the overall tread pattern.

Reference to “integral” means that in forming the outsole, any integral features forms a unitary structure with an outsole body. In one or more non-limiting embodiments, a mold is designed to include both a tread rib, cleats, channels, and the outsole body, in which case, a single injection of a polymeric material yields the unitary structure.

Reference to “affix” or “affixed” means that a pre-fabricated item connects to another item by way of gluing (e.g., adhesive or epoxy or other glue) or by direct attachment injection molding techniques.

Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or being carried out in various ways.

Turning to the figures, FIG. 1 is a schematic front view of an outsole 100 of an embodiment, the outsole 100 comprising an outsole body 102 and an external surface 104, which faces ground surfaces during use. Portions of the external surface 104, primarily projecting features, are in contact with the ground surfaces during use. The outsole body 102 comprises a polymeric material that is suitable for indoor and/or outdoor conditions. A preferred polymeric material for the outsole body 100 is a thermoplastic polymer. Exemplary non-limiting thermoplastic polymers are selected from the group consisting of natural rubber; thermoplastic rubber (TPR), e.g., styrene-butadiene-styrene (SBS) or styrene-ethylene/butylene-styrene (SEBS) block co-polymers; nitrile; thermoplastic polyurethane; and polyvinyl chloride. The outsole 100 may be formed by injection molding the polymeric material into a mold cavity of a desired tread pattern having projecting features.

A mold for the outsole is prepared according to desired design features. One or more projecting features of the outsole tread pattern, include but are not limited to: a toe 108, a heel strike 112, and one or more cleats 114. A heel 110 is also a design feature. Channels 116 are located among and between the projecting features and are included as part of the overall tread pattern. Channels 116 do not protrude from the external surface 104, rather walls of the projecting features define the channels. Tread rib 124 is also an integrally-formed feature in this embodiment.

The outsole 100 has three areas: a forefoot area 118, a shank area 120, and a heel area 122. The outsole 100 is a unitary piece in that the forefoot area 118, the shank 120, and the heel area 122 are formed in the same mold by injection molding. The heal area 122 includes the heel 110 and extends to the heel kick 112. The heal area 122 also has a cleat 114 and a tread rib 124. The shank 120 is between the heel area 122 and the forefoot area 118. The shank area 120 generally does not include any projecting features. The shank area 120 may contain indicia regarding the shoe size and brand name. The forefoot area 118 includes the toe 108; a plurality of cleats 114 and corresponding channels 116 and at least one tread rib 124. The forefoot area 118 is from the forward-most part of the outsole 100 to the shank area 120.

FIG. 2 is a schematic front view of an outsole 200 of another embodiment, the outsole 200 comprising an outsole body 202 and an external surface 204, which faces ground surfaces during use. Portions of the external surface 204, primarily projecting portions, are in contact with the ground surfaces during use. The outsole body 202 comprises one or more polymeric materials that are suitable for outdoor conditions. Preferred polymeric materials for portions of the outsole body 200 are thermoplastic polymers. Exemplary non-limiting thermoplastic polymers are independently selected from the group consisting of rubber, thermoplastic polyurethane, and polyvinyl chloride. The outsole 200 is formed by assembling three parts that are independently injection molding a polymeric material into a mold cavity of a desired design. The three parts are a forefoot pod 217, a center shank 219, and a heel pod 210. Generally, the forefoot and heel pods are designed with projecting features to form a tread pattern.

One or more projecting features of the outsole tread pattern include but are not limited to: a toe 208, a heel strike 212, and one or more cleats 214. Channels 216 are located among and between the projecting features and are included as part of the overall tread pattern. Channels 216 do not protrude from the external surface 204, rather walls of the projecting features define the channels. Tread rib 224 is also a feature in this embodiment, which is integrally-formed in its respective forefoot pod 219 or heel pod 210.

The outsole 200 has three areas: a forefoot area 218, which is the forefoot pod 217; a shank area 220, which is the center shank 219; and a heel area 222, which is the heel pod 210. The outsole 200 is a combination of three pieces, each made separately and assembled in combination to form the outsole 200. The heal pod 210 includes the heel kick 212, cleats 214, and channels 216, along with a tread rib 224. The shank area 220 is between the heel area 222 and the forefoot area 218. The shank area 220 generally does not include any projecting features. The shank area 220 may contain indicia regarding the shoe size and brand name. The forefoot area 218 includes the toe 208; a plurality of cleats 214 and corresponding channels 116 and at least one tread rib 224. The forefoot area 218 is from the forward-most part of the outsole 200 to the shank area 220.

FIG. 3 is a schematic close-up view of the outsole 200 including a tread rib 224, which is located in a channel 216 and adjacent to a first cleat 214 a and a second cleat 214 b. The tread rib 224 is substantially perpendicular to a wall of each of the first and second cleats 214 a, 214 b. The tread rib 224 is also connected to a wall of each of the first and second cleats 214 a, 214 b. The tread rib 224 has a length “L”, which in the embodiment of FIG. 3 spans the distance between the first and second cleats 214 a, 214 b.

FIG. 4 is a schematic cross-section view of outsole 200 having an outsole body 202 and an external surface 204. The tread rib 224 is located in a channel 216 defined by cleats 214, which have walls 215. The tread rib 224 has a width “W”. The tread rib 224 also has a height “H-1” relative to the external surface 204, which is the distance that the tread rib 224 protrudes from the outsole body 202. The cleats 214 also have a distance that they protrude from the outsole body “H-2”. “H-1” for the tread rib 224 is chosen based on the degree of useful life that is to be conveyed upon leveling of the tread rib with its adjacent projecting feature. When H-1 is 50% of H-2, then upon leveling tread rib with its adjacent projecting feature, there is 50% useful life remaining in the tread pattern. H-1 may be 10-90%, or 40-60% of H-2 as desired.

An aspect ratio of the tread rib 224 is defined as the ratio of L:W. The aspect ratio may be in the range of 1.5:1 to 10:1.

FIG. 5 is a plan side view of a boot 302 comprising an upper 304 affixed to an outsole 300, which may be according to any embodiment disclosed herein. The upper 304 comprises an upper body 310, which may have additional design features to facilitate donning and removing the boot by a wearer.

Reference throughout this specification to “one embodiment,” “certain embodiments,” “various embodiments,” “one or more embodiments” or “an embodiment” means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Thus, the appearances of the phrases such as “in one or more embodiments,” “in certain embodiments,” “in various embodiments,” “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily referring to the same embodiment of the disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

Although the disclosure herein provided a description with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope thereof. Thus, it is intended that the present disclosure include modifications and variations that are within the scope of the appended claims and their equivalents. 

What is claimed is:
 1. A polymeric outsole for an article of footwear comprising: an outsole body and a tread pattern that comprises a plurality of projecting features and channels between the projecting features; and a first tread rib adjacent to a first projecting feature, the first tread rib protruding a first distance from the outsole body that is shorter than a second distance that the first projecting feature protrudes from the outsole body.
 2. The polymeric outsole of claim 1, wherein the projecting features comprise one or more of: a toe, a heel strike, and a cleat.
 3. The polymeric outsole of claim 1, wherein the first tread rib is located in a first channel of the outsole body.
 4. The polymeric outsole of claim 3, wherein the first tread rib is integral to the first channel.
 5. The polymeric outsole of claim 3, wherein the first tread rib is affixed in the first channel.
 6. The polymeric outsole of claim 1, wherein the first tread rib is substantially perpendicular to the first projecting feature.
 7. The polymeric outsole of claim 1, wherein the first tread rib is connected to a side surface of the first projecting feature.
 8. The polymeric outsole of claim 1, wherein the first tread rib is effective as a wear indicator to indicate remaining useful life of the first projecting feature whereby during a first duration of wear, the first tread rib is not in contact with a ground surface while the first projecting feature is in contact with the ground surface, and during a second duration of wear, both the first tread rib and the first projecting feature are in contact with the ground surface.
 9. The polymeric outsole of claim 8, wherein the first distance that the first tread rib protrudes from the outsole body is in a range of from about 10 to about 90% of the second distance that the first projecting feature protrudes from the outsole body whereby the remaining useful life of the first projecting feature during the second duration is from about 90% to about 10%.
 10. The polymeric outsole of claim 9, wherein the first distance that the first tread rib protrudes from the outsole body is about 50% of the second distance that the first projecting feature protrudes from the outsole body whereby the remaining useful life of the first projecting feature during the second duration is about 50%.
 11. The polymeric outsole of claim 1, wherein the outsole comprises a thermoplastic polymer selected from the group consisting of: natural rubber, styrene-butadiene-styrene (SBS), styrene-ethylene/butylene-styrene (SEBS) block co-polymer, thermoplastic polyurethane, and polyvinyl chloride.
 12. The polymeric outsole of claim 1 further comprising a second tread rib adjacent to a second projecting feature, wherein the first tread rib is located in a channel of a forefoot area of the outsole and the second tread rib located in a channel in a heel area of the outsole.
 13. The polymeric outsole of claim 1, the first tread rib comprises an aspect ratio in the range of about 1.5:1 to 10:1.
 14. A polymeric outsole for an article of footwear comprising: an outsole body and a tread pattern that comprises a plurality of projecting features and channels between the projecting features; and a first tread rib adjacent to a first projecting feature selected from the group consisting of: a toe, a heel strike, and a cleat; the first tread rib being in a first channel of the outsole body and protruding a first distance from the outsole body that is shorter than a second distance that the first projecting feature protrudes from the outsole body; wherein the first tread rib is effective as a wear indicator to indicate remaining useful life of the first projecting feature whereby during a first duration of wear, the first tread rib is not in contact with a ground surface while the first projecting feature is in contact with the ground surface, and during a second duration of wear, both the first tread rib and the first projecting feature are in contact with the ground surface.
 15. The polymeric outsole of claim 14, wherein the first distance that the first tread rib protrudes from the outsole body is about 50% of the second distance that the first projecting feature protrudes from the outsole body whereby the remaining useful life of the first projecting feature during the second duration is about 50%.
 16. The polymeric outsole of claim 14, wherein the outsole comprises a thermoplastic polymer selected from the group consisting of natural rubber, styrene-butadiene-styrene (SBS), styrene-ethylene/butylene-styrene (SEBS) block co-polymer, thermoplastic polyurethane, and polyvinyl chloride.
 17. The polymeric outsole of claim 14 further comprising a second tread rib adjacent to a second projecting feature, wherein the first tread rib is substantially perpendicular to a cleat and is integral to a channel of a forefoot area of the outsole and the second tread rib is substantially perpendicular to a cleat and is integral to a channel in a heel area of the outsole.
 18. An article of footwear comprising: the polymeric outsole according to claim 1; and an upper affixed to the outsole.
 19. A method of making an article of footwear comprising: obtaining the polymeric outsole according to claim 1; and affixing an upper to the polymeric outsole.
 20. A method of providing tread wear indication, the method comprising: obtaining an article of footwear according to claim 18; wearing the article of footwear; and observing the tread rib relative to the projecting features for an indication of remaining useful life transport of the projecting features. 